g(m2)-ganglioside and Peripheral-Nervous-System-Diseases

Monolithic columns containing ganglioside GM2 and GM3 mimics were prepared for selective removal of serum anti-ganglioside antibodies from patients with acute and chronic immune-mediated neuropathies. ELISA results demonstrated that anti-GM2 IgM antibodies in human sera and a mouse monoclonal anti-GM2 antibody were specifically and selectively adsorbed by monolithic GM2 mimic columns and not by blank monolithic columns or monolithic GM3 mimic columns. In control studies, serum antibodies against the ganglioside GQ1b from another neuropathy patient were not depleted by monolithic GM2 mimic columns. Fluorescence microscopy with FITC-conjugated anti-human immunoglobulin antibodies showed that the immobilized ganglioside mimics were evenly distributed along the column. The columns were able to capture ∼95% of the anti-GM2 antibodies of patients after only 2 min of incubation. A monolithic column of 4.4 μL can deplete 28.2 μL of undiluted serum. These columns are potential diagnostic and therapeutic tools for neuropathies related to anti-ganglioside antibodies.

Topics: Adsorption; Animals; Antibodies, Monoclonal; Chemistry, Pharmaceutical; Drug Design; Enzyme-Linked Immunosorbent Assay; Fluorescein-5-isothiocyanate; G(M2) Ganglioside; Gangliosides; Humans; Immunoglobulin M; Mice; Microscopy, Fluorescence; Peripheral Nervous System; Peripheral Nervous System Diseases

We describe a patient with a pure motor chronic demyelinating polyneuropathy with an IgM monoclonal component showing anti-GM2, GalNAc-GD1a and GalNAc-GM1b reactivity whose common epitope appears to be -[GalNAcbeta1-4Gal(3-2alphaNeuAc)beta1]. We used intracellular recording to study how IgM from this patient affected neurotransmitter release in the mouse diaphragm in vitro. Adding serum (and specifically, the purified monoclonal IgM component) blocked the nerve-evoked response in both quantal content and evoked endplate potential (EPP) amplitude in a complement-independent and reversible manner. The IgM increased the frequency of spontaneous miniature endplate potentials (MEPPs) in a complement-dependent and reversible manner but had no effect on MEPP amplitude.

Topics: Adult; Animals; Antibodies, Monoclonal; Antibody Specificity; Blood Physiological Phenomena; Chronic Disease; Demyelinating Diseases; Diaphragm; Electrophysiology; G(M1) Ganglioside; G(M2) Ganglioside; Gangliosides; Humans; Immunoglobulin M; Male; Mice; Motor Endplate; Neuromuscular Junction; Neurotransmitter Agents; Peripheral Nervous System Diseases; Reference Values

GM2 ganglioside is a potential peripheral nerve antigen for neuropathy-associated autoantibodies. However little data are available on their pathogenic effects, if any. In this study we have screened both neuropathy-associated and control sera for anti-GM2 antibodies and subsequently used high titre sera for immunohistological and complement mediated cytotoxicity studies. We identified abnormally elevated anti-GM2 antisera in the normal population, as well as in patients with peripheral neuropathies and other neurological diseases. GM2 antibodies were either mono-reactive, cross-reactive with GM1a, or cross-reactive with GalNAc-GM1b and/or GalNAc-GD1a. All GM2 antisera from neuropathy subjects and normal controls bound to, and were capable of complement-mediated lysis of the NSC-34 cell line which expresses high levels of membrane-associated GM2. However, in immunohistological studies on human and rodent peripheral nervous system tissues, no specific binding was seen with GM2 antisera, either cross-reactive with GalNAc-GM1b and GalNAc-GDla, or with GM1a. These data indicate that although GM2 antisera can lyse neural membranes containing GM2, this antigen(s) is not detectable by standard immunohistological techniques in human or rodent peripheral nerve. This raises doubts about their pathophysiological significance in human autoimmune neuropathy.

Topics: Adolescent; Adult; Amyotrophic Lateral Sclerosis; Autoantibodies; Case-Control Studies; Cell Line; Cross Reactions; Cytotoxicity, Immunologic; G(M2) Ganglioside; Guillain-Barre Syndrome; Humans; Immunohistochemistry; Middle Aged; Motor Neuron Disease; Peripheral Nervous System Diseases

After treatment of melanomas with anti-GD2 monoclonal antibody (MAb) (14G2a), some patients develop sensorimotor demyelinating polyneuropathy with and without the syndrome of inappropriate antidiuretic hormone (SIADH). To clarify what causes the neurotoxicity of anti-GD2 MAb, we investigated the immunohistochemical localization of GD2 in the human nervous system. Anti-GD2 MAb (14G2a) reacted with the myelin sheaths in the peripheral nerves as well as with the pituicyte cytoplasm in the posterior lobe of the pituitary gland. We assume that the binding of anti-GD2 MAb to peripheral nerve myelin and the pituicytes in the posterior pituitary causes sensorimotor demyelinating neuropathy and SIADH.

Topics: Animals; Antibodies, Monoclonal; Biopsy; Central Nervous System; Demyelinating Diseases; G(M2) Ganglioside; Humans; Inappropriate ADH Syndrome; Melanoma; Mice; Myelin Sheath; Neurotoxins; Oculomotor Nerve; Peripheral Nervous System Diseases; Pituitary Gland; Sural Nerve; Tibial Nerve; Trochlear Nerve

The authors report on a Portuguese family with 3 adult brothers affected with GM2-gangliosidosis (B1 variant) in a sibship of 4, and more specifically on one of these brothers with neurological onset at the age of 17. Psychosis, lower motoneuron involvement and dysarthria were predominant in two of the cases; the third had a cerebellar symptomatology. Hexosaminidase A activity, studied in leukocytes, was profoundly deficient when measured using the specific sulfated substrate, but nearly normal using a conventional assay (non-sulfated substrate). These results established the diagnosis of the unusual enzymological form of GM2-gangliosidosis known as the B1 variant, which had so far not been associated with an adult phenotype. Molecular studies are in progress to study genotype/phenotype correlations in this family in comparison with known mutations in the B1 variant and in adult GM2-gangliosidosis. This report also emphasizes that a metabolic etiology, leading to genetic counselling, should be considered in some familial degenerative neurological disorders.

Topics: Adolescent; Adult; beta-N-Acetylhexosaminidases; Central Nervous System Diseases; G(M2) Ganglioside; Genetic Variation; Hexosaminidase A; Humans; Male; Muscular Atrophy; Mutation; Peripheral Nervous System Diseases; Portugal; Tay-Sachs Disease

Antibodies directed against ganglioside GM1 or sulfatides are frequently associated with motor or sensorimotor neuropathies. To establish the prevalence of such anti-glycosphingolipid autoantibodies in autoimmune disorders and to determine whether they contribute to neurologic symptoms in those individuals, we measured these antibodies by enzyme-linked immunosorbent assay (ELISA) in serum samples from rheumatologic patients with and without peripheral neuropathies (PN). We tested 21 patients with systemic lupus erythematosus (9 with PN), 26 with Sjögren's syndrome (12 with PN), 34 with scleroderma (28 with PN), and 14 with rheumatoid arthritis (4 with PN). Samples from 32 normal individuals were also tested. Patients with systemic lupus erythematosus and rheumatoid arthritis had elevated concentrations of GM1 antibodies and scleroderma patients had lower levels of sulfatide antibodies compared to healthy individuals. The presence of ganglioside or sulfatide antibodies did not correlate with the development of peripheral neuropathy in these patients. These findings suggest that relatively low-titer glycosphingolipid antibodies may arise as part of a nonspecific polyclonal gammopathy in rheumatologic disorders but generally without clinical manifestation.

Topics: Adult; Autoantibodies; Enzyme-Linked Immunosorbent Assay; Female; G(M1) Ganglioside; G(M2) Ganglioside; Glycosphingolipids; Humans; Male; Middle Aged; Peripheral Nervous System Diseases; Rheumatic Diseases; Sulfoglycosphingolipids

It was previously reported that monoclonal IgM from two patients with gammopathy and neuropathy showed similar specificity by reacting with the same group of unidentified minor components in the ganglioside fractions of human nervous tissues (Ilyas, A. A., Quarles, R. H., Dalakas, M. C., and Brady, R. O. (1985) Proc. Natl. Acad. Sci. U. S. A. 82, 6697-6700). Enzymatic degradation, ion-exchange chromatography, and immunostaining of purified ganglioside standards on thin-layer chromatograms have now revealed that the antigenic glycolipids recognized by the IgM from these patients are gangliosides GalNAc beta 1-4Gal(3-2 alpha NeuAc)beta 1-4Glc beta 1-1Cer(GM2), GalNAc beta 1-4Gal(3-2 alpha NeuAc)beta 1-3GalNAc beta 1-4Gal beta 1-4Glc beta 1-1Cer (IV4GalNAcGM1b), and GalNAc beta 1-4Gal(3-2 alpha NeuAc)beta 1-3GalNAc beta 1-4 beta Gal(3-2 alpha NeuAc)beta 1-4Glc beta 1-1-Cer (IV4GalNAcGD1a). The monoclonal IgM appears to be reacting with the terminal [GalNAc beta 1-4Gal(3-2 alpha NeuAc)beta 1-] moiety shared by these three gangliosides and is a useful probe for detecting small amounts of GM2, IV4GalNAcGM1b, IV4GalNAcGD1a, and other gangliosides with the same terminal sugar configuration in tissues. Species distribution studies using the antibody revealed that GM2 is present in the brains and nerves of all species examined, while IV4GalNAcGM1b and IV4GalNAcGD1a exhibit some striking species specificity. GM2, but not IV4GalNAcGD1a, is enriched in purified myelin from human brain.

Topics: Animals; Antibodies, Monoclonal; beta-N-Acetylhexosaminidases; Brain Chemistry; Cats; Cattle; Chickens; Electrophoresis, Polyacrylamide Gel; Epitopes; G(M1) Ganglioside; G(M2) Ganglioside; Gangliosides; Guinea Pigs; Humans; Immunoglobulin M; Paraproteinemias; Peripheral Nervous System Diseases; Rabbits; Species Specificity; Subcellular Fractions